HEAT-RESISTANT COATING COMPOSITION

Abstract

According to an aspect of the present disclosure, a heat-resistant coating composition includes: an inorganic filler which is iron (Fe)-based amorphous alloy powder having an amorphous phase and an average particle diameter of 0.5 μm to 15 μm; and a binder, where the coefficient of thermal expansion of the inorganic filler is lower than the coefficient of thermal expansion of the binder.

Claims

1. A heat-resistant coating composition comprising: an inorganic filler which is iron (Fe)-based amorphous alloy powder having an amorphous phase and an average particle diameter of 0.5 μm to 15 μm; and a binder, wherein the inorganic filler has a thermal expansion coefficient lower than a thermal expansion coefficient of the binder.

2. The heat-resistant coating composition of claim 1, wherein the inorganic filler has thermal conductivity greater than thermal conductivity of the binder.

3. The heat-resistant coating composition of claim 1, wherein the heat-resistant coating composition comprises 1 wt % to 5 wt % of the inorganic filler.

4. The heat-resistant coating composition of claim 1, wherein the inorganic filler has a glass transition temperature (Tg) higher than a melting point (Tm) of the binder.

5. The heat-resistant coating composition of claim 4, wherein the binder comprises a fluorine-based resin comprising at least one of PTFE, ETFE, FEP, and PFA.

6. The heat-resistant coating composition of claim 4, wherein the inorganic filler is alloy powder comprising iron (Fe) and at least one selected from the group consisting of molybdenum (Mo), chromium (Cr), boron (B), carbon (C), nickel (Ni), cobalt (Co), silicon (Si), phosphorus (P), and niobium (Nb).

7. A heat-resistant coating member comprising: a heat-resistant coating layer formed of the heat-resistant coating composition of claim 1; and a base material on which the heat-resistant coating layer is provided.

8. The heat-resistant coated member of claim 7, wherein the heat-resistant coating layer has a thickness of 20 μm to 30 μm.

9. The heat-resistant coated member of claim 7, wherein the average particle diameter of the inorganic filler is 0.0125 times to 0.5 times of a thickness of the heat-resistant coating layer.

10. The heat-resistant coated member of claim 7, wherein at least one of the inorganic filler protrudes outwardly from a surface of the heat-resistant coating layer, and a protruding height of the inorganic filler protruding outwardly from the surface of the heat-resistant coating layer is 0.01 times to 0.1 times of a thickness of the heat-resistant coating layer.

11. The heat-resistant coated member of claim 10, wherein the protruding height is 0.1 times to 0.5 times the average particle diameter of the inorganic filler.

12. The heat-resistant coated member of claim 10, wherein when an arbitrary square area having a width of 1 cm and a length of 1 cm is defined on the surface of the heat-resistant coating layer, the inorganic filler has an area fraction of 0.3% to 1.4% in the surface.

Description

EXAMPLES

Example 1

Preparation of Heat-Resistant Coating Composition

[0108] Tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer [PFA] was mixed with an Fe-based amorphous alloy powder inorganic filler having an average particle diameter of 13 μm while adjusting the weight ratio of PFA:inorganic filler to be 96:4, so as to prepare a heat-resistant coating composition.

Examples 2 to 6

Preparation of Heat-Resistant Coating Compositions

[0109] As shown in Table 1 below, heat-resistant coating compositions were prepared while changing the composition of a fluorine-based resin in a binder, the average particle diameter of an inorganic filler, and the weight ratio of the binder and the inorganic filler.

Comparative Examples 1 to 3

Preparation of Heat-Resistant Coating Compositions

[0110] As shown in Table 1 below, a heat-resistant coating composition was prepared by selecting a fluorine-based resin of a binder, adjusting the weight mixing ratio of the binder and an inorganic filler to be 90:10, and using powder having an average particle diameter of 20 μm as the inorganic filler.

[0111] In Comparative Example 2, a coating composition containing only a binder without an inorganic filler was prepared.

TABLE-US-00001 TABLE 1 Average Weight particle Glass mixing diameter transition ratio of Melting temperature (binder: inorganic point of of inorganic inorganic filler binder filler Binder filler) (μm) (° C.) (° C.) Example 1 PFA 96:4  13 300 500 or more Example 2 PFA 99:1  12 300 500 or more Example 3 ETFE 96:4  15 270 500 or more Example 4 ETFE 95:5  5 270 500 or more Example 5 PEP 98:2  1 260 500 or more Example 6 PEP 97:3  12 260 500 or more Comparative PFA 90:10 20 300 500 or more Example 1 Comparative PEP 100:0  — 260 — Example 2

EXPERIMENTAL EXAMPLES

Experimental Examples 1 to 8

[0112] The heat-resistant coating compositions of Examples 1 to 6 and Comparative Examples 1 to 2 were applied to base materials specified in Table 2 below to form coating layers, and the non-stickiness, swelling, and impact resistance of each of the coating layers were tested.

[0113] Experimental methods and conditions are as follows, and results of the experiment and thermal characteristics of Experimental Examples 1 to 5 are shown in Tables 2 and 3 below.

[0114] 1) Non-Stickiness Test

[0115] After breaking and put eggs on the coating layers of Experimental Examples 1 to 5, 20 minutes passed until the eggs were cooked. Then, the eggs were removing with a wooden spatula, and the coating layers were wiped with soft loofah wet with a neutral detergent. These processes were set as one cycle, and the cycle was repeated ten times. Thereafter, it was evaluated with the naked eye whether egg remained on the coating layers and whether the coating layers were damaged.

[0116] 2) Impact Resistance Test

[0117] The coating layers of Experimental Examples 1 to 5 were impacted by a 500 g steel ball from a height of 50 cm with a Dupont-type impact tester according to ATSTM D2794, and then it was observed and evaluated with the naked eye whether the coating layers were cracked.

[0118] 3) Swelling Test

[0119] The surfaces of the coating layers of Experimental Examples 1 to 5, which were cured, were observed with the naked eye to evaluate whether there were swells, bubbles, or separated portions.

TABLE-US-00002 TABLE 2 Non- Impact stickiness Swelling resistance Note Experimental ⊚ ⊚ ∘ Example 1 Experimental ⊚ ⊚ ∘ Example 2 Experimental ⊚ ⊚ ∘ Example 3 Experimental ⊚ ∘ ∘ Example 4 Experimental ⊚ ∘ ∘ Example 5 Experimental ⊚ ⊚ ∘ Example 6 Experimental ∘ Δ ∘ Comparative Example 7 Example 1 Experimental ∘ ∘ Δ Comparative Example 8 Example 2

TABLE-US-00003 TABLE 3 Physical properties Coefficient Thermal of thermal conductivity expansion (W/m .Math. K, @ Material (10.sup.−6/° C.) 100° C.) Base Stainless steel 16.7 to 17.2 16.2 material (ST304) Al alloy 20 to 23 151~202 Al alloy 20 to 23 151~202 Stainless steel 16.7 to 17.2 16.2 (ST304) Stainless steel 16.7 to 17.2 16.2 (ST304) Binder PFA 93 0.24 ETFE 120 0.25 PEP 105 0.25 Inorganic Fe-based 12.5  7~11 filler amorphous alloy

[0120] The features, structures, effects, or the like illustrated as examples in the embodiments above may be combined or modified in other embodiments by those of ordinary skill in the art. Thus, these combinations and modifications should be considered as being included in the scope of the present disclosure.